-
MQTT with message retention is a pretty easy way to do this. Messages sent from Espruino’s TinyMQTT module have retention set by default. This is a good choice if you can easily have IP at both ends and you can have a slightly beefier box as a server. A Pi2 is fine.
If you are relatively new to all this NodeRed is a good choice because it has a UI to manage the design of the MQTT flows of data between your sensing devices and display, and add logic plus you can easily debug the MQTT messages flying around. However NodeRed doing any amount of work needs a beefier server, a Pi3 would be recommended.
I tried some of the examples at https://googlechrome.github.io/samples/web-bluetooth/index.html and while I could get some to work it was discouraging since, alas, Bluetooth wants to do me favors and builds in application knowledge. This is why I want more generic connectivity. I will look more into the MQTT approach but I still want to find a simple way to do an app that makes an IP connection, fetches data, and displays it.